Sewing machine



ug- 11, 9 c. s. THOMPSON ETAL 2,292,724

SEWING MACHINE, Filed April 27., m 6 Sheets- Shee't 3 I A TTORNEYS.

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1942- c. s. THOMPISOQNYJE'TAL' 2, ,7

SEWING MACHINE Fii ed April 27'', 1939' e Sheets-Sheet. 4

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ATTORNEYS.

Patented Aug. 11, 1942 UNITED STATES PATENT OFF-ICE- scwmcmonma Schweda, Chicago, 111., assignors to Union Speciai Machine Company, Chicago, Ill., a coyo- 'ration of Illinois Application 'April 21, 1939, serial No. 270,3 4

r 15 Claims. (01. 112-191) I This invention relates to sewing machines;

and it has for its chief aim to make possibleto suspend stitch-formation in a sewing'machine at gill without attendant cessation in the operation tion, we have illustrated the first and third forms respectively shown in Figs. I-VI and Figs. 16111- XVH as embodied in a chain stitch sewing machine generally of the type featured in U. S. Patent No, 2,128,120 granted to Norman V.

, Christensen and Charles F. Rubel on August 23,

vision of simple manually operable mechanism for controlling the elements which cooperate with the needles of the machines in stitch-formation,

in such manner that said elements may be prevented from taking the needle threads with consequent skipping of stitches at different times and for varying periods as the character of the work operated upon may require.

In the drawings, Fig. I is a fragmentary view partly in front elevation and partly in longitudinal section, of a sewing machine conveniently embodying the control means of our invention in one form.

Fig. 11 is a horizontal section taken as indicated by the angled arrows 11-11 in Fig. I.

Fig. III is a. view like Fig. I with the control mechanism positioned to prevent stitch-formaw tion.

Fig. IV is an end elevation of the. machine looking as indicated by the'angled arrows IVIV in Fig. I.

Fig. V is a perspective view of one of the parts of the control mechanism.

Fig. V1 is a diagrammatic view showing, how the complemental stitch-forming means of the machine is controlled in accordance with our invention.

Figs, VII and VIII are views corresponding to Figs. I and 11 showing an alternative form of our improved stitch control mechanism.

.Fig. IX is a view like Fig. VlI with the parts of the alternative form of the mechanism to prevent stitch-formation.

Figs. X, XI and KB are perspective views of certain parts of the alternative form.

Figs. XIII and XIV are views in turn like Figs. I and II showing still another alternative form of our stitch control mechanism.

Figs. XV and XVI are perspective views of certain parts of the third form of the mechanism;

Fig. XVII is a diagrammatic view showing the operation of the last referred to alternative form.

1938. The second form of our invention shown ,in Figs. VIIX[I, we have, on the other hand,

the base i of the machine frame supports the work plate 2, and beneath the latter provides journals 3 and 4 for a longitudinally-extending rotary shaft '5 which may be driven as in the patent supra. The feed bar 6 (Fig. 11) of the machine is pivoted at its rear en'dto a rocker I which is secured to a shaft 8 suitably journalled in the base I and which is oscillated for impartation of feed movements to said bar, through'a horizontal arm 9 and connecting vertical link Hi,

from a crank stud H at the left hand end of the in the usual and well known manner. The loopers l5 and I6 are secured by set screws l1 and I8 to the looper holders l9 and 20 which are fulcrumed respectively on studs 21 and 22 and which are connected for operation in unison by a link 23. The fulcrum studs 2 I, 22 for the looper holders I9, 20 are adjustable along horizontal slots 24 in the pendant wing or fin 25 of a sleeve 26 which is secured by set screws to a rock shaft 21 extending parallel to the shaft 5 and journalled at its ends in the machine base. A horizontal arm 28'clamped to the shaft 21 adjacent one end of the sleeve 26 extends rearward beneath the shaft 5 for actuation by an eccentric 29 on the latter shaft with resultant impartation of needle avoiding movements to the loopers l5, l6. Loop taking and shedding movements are on the other hand communicated to the loopers I5, 16 from another rotary actuator in the form of a crank 30 on the shaft 5, through means including a drop 1ink 3l by which said crank is connected to the horizontal arm 32 (Fig. I) of a rocker 33 (Fig. 11)

For convenience of exemplifying our inven- As shown, the rocker 33 ismounted for oscillation on a transversely extending shaft 35 fixed against rotation in the machine base I by set screws 36. The rocker 33 also has an upright arm 31, which, by means of a horizontal link 38, is coupled with the holder 20 of the looper I6.

I The mechanism featured in Figs. I-IV for controlling stitch-formation in accordance with our invention includes a control arm 46 which is separately illustrated in perspective in Fig. V. As

shown in Figs. I and III, the hub 4i of the arm 40 fits, with capacity for rotation and an endwise sliding movement, into a bore 42 in the machine base and is, in turn, axially bored to fit freely over'the shaft 2'! between a collar 43 at the outer end of said shaft and the corresponding end of the sleeve 26. The hub 4| of the control arm 40 has a segmental helical cam slot 45 which is engaged by the reduced inner end of a stud 46 screwed into the machine base from beneath. The control arm 40 is operable through a chain shown at 41 by a foot treadle or knee press (not illustrated) against the pull of a helical spring 48 in tension between said am and a fixed anchorage 49 on the machine base I. The ,downward movement of the arm 46 is limited through engagement of a lug 50 thereon with a fixed stop With the parts positioned as shown in Figs. 1, II and IV, V and in full lines in Fig. VI, the loopers l5 and IE will function in the normal manner with the needles l3 and i4 to form two separate lines of chain stitches, that is to say, the points of the loopers will reach the needles in time to take'the thread loops thrown out by the needles as the latter begin their ascent after having penetrated the fabric. Stitch-formation can, however, be interrupted at any time through actuation of the control lever 40 by downward pull upon the chain 41. Incident to such movement of the lever 46, the cam slot 45 in its hub 4| in cooperation with the fixed stud 46 causes axial shifting of the rock shaft 21 leftward from the position of Fig. I to that of Fig. HI, with the result that the fulcrum studs I I, 22 for the loopers l5 and I6 are correspondingly shifted leftw'ard relative to the links 23 and 38. As a consequence, the range of movement of the loopers I5 and I6 is shifted to the extent shown by the dotted lines in Fig. VI so thatthe points of the loopers will fail to reach the needles until the eyes of the latter and the thread loops projecting from them are above the paths of said points,

for operation by downward pull upon a chain 410 against the yielding resistance of a spring 48a,

which, in this instance, is of the torsion variety coiled about the hub of the lever with one of its ends hooked about a fixed stud 46a on the machinebase la, and with its other end underreaching said lever adjacent the fulcrum of the latter. Normally the lever 40a occupies the position shown in Fig. VII with its top edge abutting a lateral projection 58 at the top of a stop member 59 secured to the front of the base la. A

- engaging said shaft in the interval between said collar and the inner end of the bearing bushing 51 (Fig. VIII), and coupled through a vertical link 64 with the pivot stud 54 of the horizontal link 38a. Another torsion spring 65 surrounding the inner end of the bearing bushing is relied upon to yieldingly urge the arm 63 upwardly thereby to normally keep the stud 54 at the top of the inclined slot 55 in the arm 31a of the rocker 33a as shown in Fig. VII.

As the control lever a is depressed to move the shaft '56 counter-clockwise, the collar 6| in following suit, depresses the arm 63 as a consequence of which the stud 54 is moved downward in the slot 55 of the rocker arm 31a and the range of movement of the loopers I50, I60. is shifted to the extent shown in Fig. IX and the points of said loopers thereby prevented from reaching the needles in time to catch the thread loops thrown out from them as was the case in the first described embodiment.

All the other elements not specifically referred to in connection with Figs; VII-XI having their counterparts in the first described embodiment,

- are identified by the same reference numerals with resultant temporary preclusion of stitch the loopers I5a, l6a for the purpose of stitch pre vention is had through shifting of the pivot stud 54 at the rear end of the link 38a downwardly in an inclined slot at the top of the vertical arm 31a of the rocker 33a, from the normal position of Fig. VI! to the position of Fig. IX. The means for so shifting the pivot stud 54 includes a control lever 40a at the outer end of a short shaft 56 which is journalled in a bearing bushing set into the front of the machine base la at right angles to the shaft 5a. As in the first described form of our invention, the control lever 46a is arranged previously employed with addition in each instance of the letter "a for convenience of distinction.

In the third embodiment of our invention illustrated in Figs. X[lI--XVII, the link 36?) by which the loopers l5b, I6b are coupled with the upright arm 3'") of the rocker 33b, is formed in two parts or sections 61, 68 with the contiguous ends of said parts interconnected by a stud 66. Interruption of stitch-formation is here effected through modification of the looper action by downward movement of the pivot 69 from the normal position shown in Fig. XIII and in full lines in diagrammatic Fig, XVII, to the dotted line position in the latter illustration. The control lever 46b is in this instance freely fulcrumed intermediate-its ends on the outer end of the transverse shaft 35b carrying the rocker 33b, and held in place on said shaft by a collar 16. A torsion spring 46b tends to turn the lever 46b clockwise in Fig. XIII, such movement being limited through engagement of an adjustable screw H in a lateral lug 12 on the short arm of said lever with the surface 58b of the machine base lb. Counter-clockwise movement of the lever 46b is limited, on the other hand, through engagement of adjustable screw I3 in a. lug 14 on the longer arm of said lever 40b with the surface 5": of the machine base lb. Through a vertical link I5, the short. arm of the. lever 46b is coupled with the common pivot stud 69 connecting the two components 61, 66 of the link 36b. As shown, in Fig.

XVI, the vertical link 15 has a clevis at the'botand the corresponding end of the'link component 5 =68 are apertured for passage of the shank of the stud 69, which is secured to said link component by a set screw 16 and which has a ball head engaged by the split end bearing 11 of the link component 61. In this instance, the control lever 40b is intended to be actuated from a knee press or foot treadle (not illustrated) by upward thrust upon the link bar shown at "b. Here again those elements not specifically referred to but having their counterparts in the first described embodii5 skilled in the art that it is applicable with attainment of all the advantages hereinbefore pointed out, in connection with sewing machines wherein but a singlelooper is employed.

Having thus described our invention, we claim: 1. In a, sewing machine, a thread carrying needle; a reciprocating looper normally cooperating with the needle to form seam stitches; and controlling means operable at will while the machine is running to shift the range of movement of the looper so that the point of the latter-is prevented from reaching the needle until after the needle extending at right angles to said fulcrum; means eye and the thread loop projecting therefrom are. beyond the reach of said point, for the purpose of temporarily precluding stitch formation.

2. In a sewing machine, a thread carrying needle; a reciprocating thread carrying looper norchine is running to shift the range of movement of the looper so that the point of the looper is prevented from reaching the needle until the eye in the latter and the thread loop projecting therefrom are beyond the reach of said point, for the purpose of temporarily precluding stitch formation.

3. In a sewing machine, a thread carrying needle; a pivoted looper normally cooperating with the needle to form seam stitches; means for oscillating the looper; and controlling means for the oscillating means operative at will while the machine is running to shift the range of movement of the looper so that the point thereof is prevented from reaching theneedle until after the eye in the latter and the thread loop projecting therefrom are beyond the reach of said point, for

the purpose of temporarily precluding stitch forother instrumentality until the thread loop.

thrown out from the latter is beyond the path of said projection, for the purpose of temporarily 75 precluding stitch formation.

5. In a sewing machine, a needle and a looper to normally cooperate therewith in stitchformation; a pivoted carrier for the looper; actuating means connected to the looper carrier beyond its pivot for imparting loop taking and shedding movements thereto; and controlling means operable at will while the machine is running for relatively shifting the looper carrier pivot and the point of connection of the actuating means to temporarily prevent cooperation of the looper with the needle and thereby avoid stitch formation.

6. In a sewing machine, a needle; a pivotally supported looper normally cooperating with the needle in forming seam stitches; means for oscillating the looper; and mechanism for shifting the fulcrum axis of the looper at will relative to the oscillating means while the machine is running, to prevent said looper from cooperating with the needle and thus preclude stitch formation.

'7. In a sewing machine, a needle; a looper; a fulcrum about which the looper is oscillatable for needle loop taking and shedding; means for oscillating the looper; a sleeve carrying the looper fulcrum and rockable about an axis -at right angles to said fulcrum for impartation of needle avoiding movements to the looper; means for rocking the sleeve; and mechanism for shifting the sleeve axially 'at will while the machine is running, to prevent the looper from cooperating with the needle. and thus preclude stitch formation.

8. In a sewing machine, a needle; a looper; a fulcrum about which the looper is oscillatable for needle loop taking and shedding; a sleevec'arrying the looper fulcrum and aifixed to a rock shaft for rocking the shaft; and mechanism for shifting the shaft axially at .will while the machine is running, to prevent the looper from cooperating with the needle and thus preclude stitch formation. said mechanism including a control lever with a hub rotatively free on said shaft but restrained against independent axial movement thereon, and a fixed member engaging a circumferential cam slot in the lever hub whereby, when the lever is actuated, the sleeve is axially shifted as aforesaid.

9. In a sewing machine, a needle; a looper; a fulcrum about which the looperis oscillatable for needle loop taking and shedding; a sleeve carrying the looper fulcrum and afiixed to a shaft extending at right angles to the fulcrum axis of the looper; means for rocking the shaft; and

' Y mechanism for shifting the shaft axially at will while the machine is running, to prevent the looper'from cooperating with the needle and thus preclude stitch formation, said mechanism including a control lever with a hub rotatively free on said shaft but restrained against independent axial movement thereon, a fixed member engaging a circumferential cam slot in the lever hub whereby, when the lever is actuated, the sleeve is axially shifted as aforesaid, yielding means to maintain the control lever in normal position, and stop means for limiting the operating movement of the control lever.

10. In a sewing machine, a needle; a pivotally supported looper normally cooperating with the needleto form seam stitches; means for oscillating the looper including a rocker with an arm; a coupling link connected by a pivot at one end to the looper and by another pivot at its other end to the rocker arm; and control means whereby the last mentioned pivot can be shifted at will while the machine is running, lengthwise of the rocker so that its point will not reach the needle in time to catch the thread loop thrown out from the latter, thereby to temporarily preclude stitch formation.

11. In a sewing machine, aneedle; a pivotally supported looper normally cooperating with the needle to form seam stitches; means foroscillating the looper including a rocker with an arm; a coupling link connected by a pivot at one end to the looper and having a pivot stud at the other end engaging an inclined slot in the rockerarm; and control mechanism whereby the stud may be shifted at will along the slot in the rocker arm while the machine is running, toshift the range of movement of the looper so that its point will not reach the needle in time to catch the thread loop thrown out from the latter, thereby to temporarily preclude stitch formation.

12. In a sewing machine, a needle; a pivotally supported looper normally cooperating with the needle to form seam stitches; means for oscillating the loper including a rocker with an arm; a

' coupling link connected bya pivot at one end to .the looper and having a pivot stud at the other end engaging an inclined slot in the rocker arm; and control mechanism whereby the pivot stud may be shifted atwill along the slot in the rocker arm while the machine is running, to shift the range of movement of the looper so that its point will not reach the needle in time to catch the thread loop thrown out from the latter, thereby to temporarily preclude stitch formation, said mechanism including a. control lever, an arm loosely fulcrumed on the axis of the control lever;

arm to shift the range of movement of the looper being composed of two interpivoted components; and mechanism whereby the pivot interconnecting the two link components may be shifted at will while the machine is running, to shift the range of movement of the looper so that its, point will not reach the needle in time to catch the thread loop thrown out from the latter, thereby to temporarily preclude stitch formation.

14. In a sewing machine, a needle; -a pivotally supported looper normally cooperating with the needle to form seam stitches; means for oscillating the looper including a rocker arm and a link coupling the looper with the rocker arm, said link being composed of two interpivoted components; and mechanism whereby the pivot interconnccting the two link components may be shifted at will while the machine is running, to shlftthe range of movement of the looper so that its point willnot reach the needle in time to catch the a link connecting said arm withth'e shiftable stud aforesaid; yielding means influential upon said arm to normally maintain the shiftable stud at one end of the slot in the rocker arm; a collar aflixed to'the axis of the control lever having a lateral projection which over reaches the arm thread loop thrown out from the latter, thereby to temporarily preclude stitch formation, said mechanism including a control lever, a link by which the control lever is coupled with the pivot interconnecting the two link components, means for yieldingly maintaining the lever against a fixed stop with the parts in their normal positions, and means for limiting the operative movement of the lever.

15. In a sewing machine, a needle; a pivotally supported looper normally cooperating with the needle to form seam stitches; means for oscillating the looper including a rocker arm and a link coupling the looper with the rocker arm, said link being composed of two interpivoted components: and mechanism whereby the pivot interconnecting the two link components may be shifted at will while the machine is running, to shift the range of movement of the looper so that its point will not reach the needle in time to catch the thread loop thrown out from the latter, thereby to temporarily preclude stitch formation, said mechanism including a control lever rotatively free on the axis of the rocker arm, a link by which the control lever is coupled with the pivot interconnecting the two link components, means for I yieldingly maintaining, the lever against a fixed stop with the parts in their normal positions, and means for limiting the operative movement of the lever. I

' CHARLES S. THOMPSON.

HAROLD J. LE YESCONTE. ALBERT M. SCHWEDA. 

